Production and direct measurement of circularly polarized vacuum-ultraviolet light with multireflection optics

Abstract
The conversion of linearly polarized synchrotron radiation to circular polarization has been successfully achieved beyond the LiF transmission cutoff in the vacuum ultraviolet by utilizing a triple-reflection polarizer as a quarter-wave retarder. The Stokes parameters of the emerging beam were directly measured at 30 eV with a reflection-type polarimeter as a function of the rotation angle of the ‘‘circular polarizer’’ around the optical axis. The results show that a degree of circular polarization of up to ∼±82% was attained at ∼±25° rotation angles, respectively, between the incidence plane for the polarizer and the horizontal plane. This result is in good agreement with a calculation which took into account the independently measured Stokes parameters of the incoming beam.